Heat exchanger



July 26, 1932. c. w. METZGAR 1 HEAT EXCHANGER Filed Oct. 29, 1929 Kw w m W n m m J m k S v KEN N MN 5 g m. a 1111 I w 1% m M and the cylinder Patented July 26, 1932 UNITED STATESePATEN'la OFFICE CHESTER W.-ME'1ZGAR, O]? EASTON, PENNSYLVANIA, ASSIGNOR '10 INGEBSOLL-RAND COMPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JRSEY HEAT nxcmnena' Application filed October 28, 1929. Serial No. 408,216.

This invention relates to heat exchanger apparatus, and more particularly to devices adapted to be used in conjunction with compressors for cooling the air between stages of compression or between the final stage of compression and the storage receiver,

The objects of the invention are to increase the general efliciency of cooling apparatus of this type, to materially reduce the cooling surface of the exchanger, and to minimize the amount of cooling liquid required for extracting the heat from the fluid intended to be cooled.

Another desirable object is to prevent the flow of condensate from the exchanger into the machine to which the exchanger may be attached.

Other objects will be in part obvious and in part pointed out hereinafter.

In the accompanying drawing taken in conjunction with the following specification,

Figure 1 is a longitudinal sectional elevation of a heat exchanger constructed in accordance with the practice of the invention, and

Figures 2 and 3 are transverse views taken on the lines 2 2 and 3-3 respectively of Figure 1.

Referring more particularly to the drawing, A designates generally aheat exchanger comprising'a casing B having integral legs 0 and D to seat on the cylinders E and F of a compressor or similar machine.

Only a portion of each cylinder E and F is shown to illustrate a practical application of the invention and the cylinder F may be considered as bein the low pressure cylinder 1% a high pressure cylinder.

In accordance with the practice of the invention the leg D is provided with a passage G into which the fluid compressed by the low premure cylinder F is discharged. The passage G merges into an annular passage H formed by a belt J which encircles the casing B. Preferably located in the top of the casing B is an inlet opening K through which the fluid flows from the passage H into the casing B.

The leg C is likewise provided with a pas sage L opening into an annular passage 0 in a belt P which is preferably an integral portion of the casing B. Communication between the passage 0 and the interior of the casin B is afiorded through an outlet opening'ts preferably in the top of thecasing B through which the fluid compressed. by the that pressure fluid may only enter into and pass from the casing at the upper portion thereof. This is desirable since it prevents the flow of condensate from the easing into the compressor cylinders.

Accordingto the arrangement shown any moisture which becomes separated from the fluid may precipitate to the bottom of the casing from whence it may flow through a condensate outlet R preferably located adjacent the leg C. The condensate is conveyed from the outlet opening R by a pipe S leading to a trap T disposed within the leg C to form a condensate chamber U therein. The trap T may be an integral part of the leg C and has an opening V normally closed by a cover plate Threaded into the cover plate W, or otherwise suitably secured thereto, is a plu X having a passage or port Y through which the condensate drained into the chamber U may flow from the said chamber through a pipe Z.

Disposed slidably within the plug X to control the port Y is a valve 6 which is adapted to be actuated by a float 0 supported by the condensate within the chamber U and is pivoted as at (i to a lug 6 carried by the cover plate W. The means forming a connection between the float 0 and the valve 6 may be in the form of a depending finger f which may extend through a slot (not shown) in the needle valve 1; to actuate said needle valve in accordance with the rise and fall of the condensate within the chamber U.

The element or elements whereby the fluid is cooled comprises a pair of cooling units 9 and I inserted into the casing B from the opposite ends thereof. The cooling units are identical in all respects. Each unit comprises an outer tube sheet j which may be suitably secured to the ends of the casing by means of bolts k. The tube sheet 7' supports a series of rows of tubes which extend through the casing to an intermediate point thereof and are supported at their inner end: by a tube sheet 1?.

The tube sheet 12 carries a water head g having a chamber 1' for water which may be divided into compartments by strips 8 of wood or similar material so spaced that each compartment will afi'ord communication between two adjacent rows of tubes. This may be readily accomplished by disposing the strips bolts t, is an outer'water head u having fluid leaving the last pass of the unit the first pass of the unit h the casin s between alternate layers of tubes so that the cooling liquid discharged from one row of tubes may flow through the compartments into another row.

Secured to the outer tube sheet j, as by a chamber '0 into the lower region of which the water may be introduced by a pipe w leading from a suitable source of supply. 'At the upper portion of the chamber 41 is an outlet opening as through which the water flowing from the upper row of tubes 0 may pass into a discharge pipe y. The chamber '0 is also divided into compartments which are separated by ribs 2 carried by the head u and strips 8 are seated in the ribs 2 and lie between alternate rows of tubes 0, but stag red with respect tothe strips 8 in the heaf q.

To the end that the fluid'intended to be cooled may be brought into intimate contact with'a maximum coolin area of the tubes 0 the casing B is provide with bafiies 2 which are arranged in staggered formation so that the fluid flowing through the casing B isdi- .rected transversely of the tubes. Any suitable number of baflles may be provided for this urpose. In the drawing three bafiles are s own associated with each unit, two being disposed on one side of the casing B and one on the opposite side. In the case where three bafiles are used four passes for the fluid are formed on each unit and, in the construction shown, considering the fluid as flowin from the low ressure cylinder to the high pressure cylin er the tube plate 1) of the unit 9 serves as a bafile for directing the fluid to the first pass of the unit h.

In order to'provide a free path for tltie 0 provided with an offset portion 3 to orm a chamber or passage 4 through which the fluid ma flow.

ractice the foregoing described apparatus lias been found to be unusually eflicient and'its advantages reside chiefly in the fact that an exchanger constructed in accordance with the practice of the invention requires materially less cooling surface to extractthe heat from a given output volume of a compressor than is the case with other known structures of this type.

This advantage is derived b using a plu-' rality of cooling units of lengt of approximately one he f or less than one half the length of the'casing wherein they are disposed. In consequence, the cooling water supplied to each unit remains therein for a considerably shorter period of time than is the case in exchangers having cooling tubes extending from one end of the casing to the other. Moreover, by using a plurality of cooling units -in the manner shown the fluid entering the inlet 0 ning K will not come in contact with the ii ating unit disposed remotely therefrom, as for instance the unit h, until the greater ortion of heat has been extracted from the uid by the unit 9 which lies adjacent the inlet opening. This advantage is obtained in structures such as that disclosed where each unit is separately connected to the supply of cooling liquid or where the inner heads are suitably connected so that the water may flow from one unit to the other.

In practice, it has been found that when the compressor is operating at full load the maximum temperature of the cooling liquid in the units is maintained within approximately twenty degrees Fahrenheit of the normal water temperature. This is extremely desirable, particularly in apparatus'where the cooling liquid is employed for other cooling purposes upon leavlng the exchanger, as

for instance, for use in the water jacket of the machine to which the exchanger is connected. The water discharged from the exchan er will then still be sufliciently cool for t is additional service and due to the moderate increase of its temperature the water will supply suflicient warmth to the cylinders to assure a' uniform distribution of the lubricant therein.

In this connection it may be stated that under the same conditions, an exchanger such as that herein described, produces the desirable results stated with a water consumption of considerably less than one half that required by the old type of exchanger.

Another very desirable advantage of the present invention over other types of exchangers is, that by using a plurality of units in the same casing either one of the units may be readily removed from the casing for purposes of inspection and repairs. In such case the end of the casing from which the unit is removed may be provided with a suitable closure, and the operation of the compressor may continue while the repairs are being made to the removed unit.

By materially reducing the size of the cooling element the casin and substantially all the other elements w ich comprise the exchanger may also be proportionately decreased in size. This results in an exchanger of comparatively light weight and, in consequence, any of the elements comprising the exchanger are cheaper to manufacture and may be handled with greater ease in assembling and disassembling.

I claim:

1. A heat exchanger comprising a casing having inlet and outlet openings at the top thereof, means forming a passage to convey fluid around the casing from the bottom thereof to the inlet opening at the top, a plurality of complete cooling liquid conveying units in the casing and extending to an intermediate portion thereof, each unit comprising a plurality of rows of tubes through which said liquid flows from one to another alternately, means on the intermediate portion of the casing forming a passage to convey the fluid from one vunit to'the other, and means forming a passage to convey the fluid around the casing to the bottom thereof from the outlet opening at the top.

2. A heat exchanger comprising a casing having inlet and outlet openings at the top thereof, means forming a passage to convey fluid around the casing from the bottom thereof to the inlet opening at the top, a plurality of complete cooling liquid conveying units in the casing and extending to an intermediate portion thereof, each unit comprising a plurality of rows of tubes through which said liquid flows from one to another alternately, an outer water head for each unit at opposite ends of the casing, an inner water head for each unit at the intermediate portion of said casing, means on'the intermediate portion of the casing forming a passage to convey the fluid from one unit to the other, and means forming a passage to convey the fluid around the casing to the bottom thereof from the outlet opening at the top.

3. A heat exchanger comprising a casing having inlet and outlet openings at the top thereof, a belt extending around the casing and forming a passage to convey fluid therearound to the inlet opening at the top, a plurality of complete cooling liquid conveying units arranged tandem in the casing and extending to an intermediate portion thereof, each unit comprising a plurality of rows of tubes through which said liquid flows from one to another alternately, an offset portion on the intermediate portion of the casing forming a passage to convey fluid from one unit to the other, and a second belt extending around the casing and forming a passage to convey fluid therearound from the outlet 0 ening at the top.

4. A eat exchanger comprising a casing having inlet and outlet openings at the top thereof, a belt extending around the casing and forming a passage to convey fluid therearound 'to'the inlet opening at the top, a

plurality of complete cooling liquid conveying units in the casing and extending to an intermediate portion thereof, each unit comprising a plurality of rows of tubes through which said liquid flows from one to another alternately, an outer water head for each unit at opposite ends of the casing, an inner water head for each unit at the intermediate portion of said casing, an offset portion on the intermediate portion of the casing forming a passage to convey fluid from one unit to the other, and a second belt extending around the casing and forming a passage to convey fluid therearound from the outlet opening at the top.

5. A heat exchanger comprising a casing having openings arranged above the bottom of the casing for the passage of fluid into and out of the casing, a heat-transferring ele ment in the casing, and means intermediate the ends of the casing forming passages around the casing to convey fluid to and from the openings.

- 6. A heat exchanger comprising a casing having an opening arranged above the bottom of the casing for the passage of fluid, aheat-transferring element in the casing, and means intermediate the ends of the casing extending along the side of the casing and integral therewith to form a passage for the opening.

7. A heat exchanger comprising a casing having inlet and outlet openings arranged above the bottom of the casing for conveying fluid into and from the casing, a heattransferring element in the casing, and belts encircling the casing to form passages for conveying fluid to and from the openings.

8. A heat exchanger comprising a casing having inlet and outlet openings arranged above the bottom of the casing for conveying fluid into and from the casing, a heat-transferring element in the casing, belts encircling the casing to form passages for conveying fluid to and from the openings, and support means for the casing forming continuations of the passages.

In testimony whereof I have signed this specification.

CHESTER W. METZGAR.

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